摘要
近地表层作为陆-气相互作用的重要界面,其土壤的冻融状态可直接或间接的反映陆地表对气候的响应程度。为了探讨青藏高原近地表土壤受气候变化的影响,利用青藏高原87个气象站逐日地表温度资料,结合空间分析技术和数理统计方法,将土壤冻融状态划分为三种状态,即完全冻结状态(CF)、日冻融循环状态(DFT)和完全融化状态(CT),分析青藏高原1980-2015年近地表不同冻融状态的时空变化及其与气温的关系。研究表明:青藏高原近地表土壤不同冻融状态有明显的时空差异。CF集中在11月-翌年2月,约为2 d;DFT主要出现于10月-翌年4月,每年发生约150 d;CT则主要集中于每年3-10月,出现约217 d。空间分布上,CF主要发生在高原东北部;DFT几乎遍布整个高原,且以冷季出现较多;CT与DFT呈现相反的分布特征。多年冻土区,CF和DFT状态变化较显著;而在非多年冻土区,CT状态变化幅度较大。不同冻融状态与月平均气温(Tmair)也有较好的对应关系:CF主要发生在Tmair<0℃的区间,DFT则发生在Tmair≤17℃区间内,而CT主要出现在Tmair>0℃。
As an important interface of land-air interaction,the freeze-thaw status of the near-surface layer can directly or indirectly reflect the response of land surface to climate.In order to investigate the influence of climate change on the near surface soil of the Qinghai-Tibet Plateau(QTP),this paper used the daily surface temperature data of 87 meteorological stations on the QTP.Combining spatial analysis technology with mathematical statistics,the soil freeze-thaw state was divided into three states:Complete freeze state(CF),daily freeze-thaw cycle state(DFT)and complete thaw state(CT),and the temporal and spatial changes of the different freeze-thaw states near the surface of the QTP from 1980 to 2015 and their relationship with temperature were analyzed.The results showed that there were obvious temporal and spatial differences in different freeze-thaw states near the surface of the QTP.CF was concentrated in November to February of the next year,and appeared for about 2 d.DFT mainly occurred from October to April of the following year,and about 150 d each year.CT was concentrated in March to October of each year,about 217 d.In spatial,CF mainly occurred in the northeastern part of the plateau;DFT almost distributed throughout the plateau,and occurred more days in the cold season;CT and DFT showed opposite distribution characteristics.In the permafrost regions,changes of the CF and DFT were significant;while in the non-permafrost regions,the changes of CT were significant.There is also a good correspondence between different freeze-thaw conditions and monthly mean temperature(Tmair):CF mainly occurred in the temperature range of Tmair<0℃,DFT mainly occurs in the temperature range of Tmair≤17℃,and CT occurred in the temperature range of Tmair>0℃.
作者
杨淑华
李韧
吴通华
胡国杰
肖瑶
杜宜臻
朱小凡
倪杰
YANG Shuhua;LI Ren;WU Tonghua;HU Guojie;XIAO Yao;DU Yizhen;ZHU Xiaofan;NI Jie(Cryosphere Research Station on the Qinghai-Tibet Plateau,State Key Laboratory of Cryospheric Sciences,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《冰川冻土》
CSCD
北大核心
2019年第6期1377-1387,共11页
Journal of Glaciology and Geocryology
基金
国家自然科学基金项目(41671070
41771076
41271081
41601078
41401085)
国家自然科学基金创新研究群体科学基金项目(41721091)资助
关键词
青藏高原
冻融状态
冻融天数
时空变化
气温
Qinghai-Tibet Plateau
freeze-thaw status
freeze-thaw days
spatial and temporal variation
temperature
作者简介
杨淑华(1993-),女,内蒙古丰镇市人,2018年在中国科学院西北生态环境资源研究院获硕士学位,现为中国科学院西北生态环境资源研究院在读博士研究生,从事寒区陆面过程相关研究,E-mail:shuhyang@lzb.ac.cn;通信作者:李初,E-mail:liren@lzb.ac.cn.
